ELLENVILLE, N.Y. -- The mother of a sex worker whose disappearance led to the discovery of 10 other sets of human remains in the notorious "Long Island Serial Killer" case was found dead in her apartment and another daughter has been charged in the killing, the family's attorney and police said Sunday.
The body of Mari Gilbert, 52, was found around 2:15 p.m. Saturday inside her Ellenville apartment in the Catskills, about 100 miles north of New York City, police said.
Sarra Elizabeth Gilbert, 27, was arraigned on murder and weapons possession charges, Ellenville police said in a release on Facebook.
Family attorney John Ray said Mari Gilbert was fatally stabbed. The daughter was being held without bail at the Ulster County Jail. She was scheduled to appear in court Tuesday.
Sarra Elizabeth Gilbert suffered from serious mental disabilities and had been charged several months ago with killing her dog, Ray said in a telephone interview with the Associated Press. He said she had lived on and off with her mother.
"Think about it -- a mother being murdered by your own child. Can there by anything that you can consider more horrible than that?" Ray told CBS New York.
Mari Gilbert's other daughter, Shannan Gilbert, vanished in May 2010 after fleeing the home of a client in Oak Beach, New York. The search for the missing woman eventually led to a shocking discovery: not only were her remains found along a Long Island beach, but so were those of 10 other people.
No one has ever been arrested in any of the killings. But investigators believe a possible serial killer -- perhaps more than one -- is responsible, and the unidentified culprit has been dubbed the "Long Island Serial Killer."
Gilbert's official cause of death was ruled "undetermined" in 2012, reports CBS New York. Suffolk County police have maintained that she was not an 11th victim of the suspected serial killer, but fell and drowned in a drug-induced panic in the marsh.
Ray and the woman's family, however, believe she was murdered. Gilbert made a desperate call to 911 in the hours before she disappeared, telling police she was in danger, but didn't give them her location. She ran to several Oak Beach homes, asking for help, before vanishing.
A K-9 officer and his cadaver dog were on a training mission searching for Gilbert in December 2010 when they happened upon what would become by spring of the following year 10 sets of human remains -- eight women, a man and a toddler. The remains were found strewn along several miles of thicket adjacent to Ocean Parkway, just east of Jones Beach.
The 10 other victims, including at least four other sex workers, were found about three miles west of where officials found Gilbert's body. Some of the other remains were found more than 10 miles away from Gilbert's, and officials later linked some of those body parts to dismembered victims found more than 40 miles from Ocean Parkway since 1996.
Gilbert's remains weren't discovered until December of 2011.
Family members including Sarra and Mari Gilbert spoke to "48 Hours" in an interview for an investigation into the Long Island Serial Killer case.
"She pretty much thought that, you know, it would never happen to her," Sarra Gilbert said.
Mari Gilbert had advocated for keeping the investigation into her daughter's death active.
"I just did not want to believe that she wasn't ever gonna come home," Mari Gilbert told "48 Hours."